There are several synonyms for the word "stovelength", which is a unit of measurement typically used by horse racers to indicate the distance between two horses. One such synonym is "neck", which refers to the length of a horse's neck and is often used interchangeably with stovelength. Another synonym is "head", which indicates the distance between the two horses' heads. "Nose" is also a commonly used synonym for stovelength, as it refers to the distance between the two horses' noses. Additionally, "length" can be used to describe the distance between the horses, though it is not specific to horse racing.